Ornithine aminotransferase (OAT) is a 45kD pyridoxal phosphate-dependent enzyme that catalyzes the transfer of the delta amino group of ornithine to an alpha ketoglutarate substrate. OAT and gamma aminobutyric acid transaminase (GABA-AT) belong to the same subgroup of transaminases, and in addition to sharing high sequences homology, are incativated by common inhibitors. One such inhibitor is the neurotoxin gabaculine (5-amino-1,3-cyclohexadienylcarboxylic acid), a cyclic analogue of the inhibitory neurotransmitter GABA. We were able to collect a 2.3 angstrom data set at CHESS of OAT in complex with gabaculine, and solve the structure using phases from the native protein. The complex reveals the structural basis for the "suicide" binding of gabaculine to the active site. In addition, we were able to collect data on OAT bound to a different inhibitor, L-canaline, as well as a 2.0 angstrom alpha-ketoglutarate bound data set.